The present invention relates to a keyless access sensor system and its associated sensor device for keyless access particularly, but not exclusively, for use in allowing access by an authorized user to a vehicle, building or the like. The invention also relates to a method of using a keyless access sensor system to control entry of authorized persons and to a circuit for processing signals in a keyless access sensor system.
It is important, for many reasons, to control access to premises, vehicles and personal property so that only authorized users are allowed access. Typically this is done using keys which fit a lock to allow the user of the key to open the lock and gain entry. One problem with the existing key and lock arrangements is that loss or damage to the key can render access impossible. In addition, if the key lock itself is blocked or damaged this can also prevent access. One other problem is that the use of a key requires a specific action such as unlocking a door latch with the key from the authorized person before an action of opening the door associated with the door latch. This specific action is very often not easy to accomplish, is not ergonomic and is time-consuming.
A number of solutions have been proposed to try to overcome these disadvantages. With security devices for cars, it is well known that a keyless fob can be used, such that actuation of a button on the fob generates an infrared (IR) or radio frequency (RF) signal which is detected by a sensor in the vehicle which unlocks the doors. A key is still required by the user in order to operate the ignition system. The fob also contains a lock button which generates a similar IR or RF signal to lock the vehicle. Such vehicle keyless access systems have been known for a number of years. Such systems operate on the basis that when the IR or RF “open” signal is generated by the fob, the signal is used to actuate a mechanism which unlocks the car door so that when the user pulls on the handle, the door is already unlocked. Similar arrangements may be used for building entry.
One problem with this arrangement is that the user still has to initiate a specific action such as, in the case of a fob, taking the fob in his hand and pressing on the fob button, or in the case of a magnetic card or the like, inserting the card in a slot or to present it in front of a card reader/detector or the like, in order to unlock the door and have access to the vehicle, these specific actions being time-consuming and not ergonomic.
One other problem with this arrangement is that if the user decides not to enter the vehicle but forgets to actuate the “lock” signal, the car and/or building remains open and is thus vulnerable. In addition, with existing keyless locking systems, particularly for vehicles, a conventional locking mechanism is used which is susceptible to interference by thieves to gain access to the car. For buildings, conventional locks are actuated in the same way and are susceptible to the same procedures by intruders to gain access to the premises.
It is desirable to provide a system which obviates or mitigates at least one of the above mentioned problems, and this is now provided by the present invention.